function myReject(reason) {
    // **如果 value 已经是 Promise 对象，则直接返回该 Promise 对象**
    if (reason instanceof Promise) {
        return reason;
    }
    // 如果 value 是 thenable 对象，则包装成 Promise 对象并返回
    if (reason && typeof reason.then === 'function') {
        return new Promise(function(resolve, reject) {
            reason.then(resolve, reject);
        });
    }
    return new Promise((resolve, reject) => {
        reject(reason);
    });
}
